bwhite@oucsace.cs.ohiou.edu (Bill White ) (09/14/90)
Hello. I am finishing up a very large van de graaff generator (about 4' high, fed with a 10kV charge screen, hoping for up to 1MV if I'm lucky and running in SF6). Anyhow, I need the top sphere, which should be in the range of 16 to 20 inches diameter (although anything bigger is OK too). But here's the catch -- ever try to find anyone who still knows how to spin aluminum??? So if anyone out there knows where I can get such items (four hemispheres, 16 to 20 inches diameter, aluminum; thickness not terribly vital as long as it holds its shape), please respond. I can not use salad bowls or other devices which are not true hemispheres. (Incidentally, I said four because the other two are for a particle accelerator tube). I'd like to keep the cost low here, if possible. | Bill White Internet: bwhite@oucsace.cs.ohiou.edu | | MAIER'S LAW: | | If the facts do not conform to theory, | | they must be disposed of. |
heskett@titan.tsd.arlut.utexas.edu (Donald Heskett) (09/17/90)
Unless you have some special reason for using aluminum spheres, I suggest you try to find globes (as in world map globes) of the proper size for your use. They have been put to such use before.
logajan@ns.network.com (John Logajan) (09/17/90)
bwhite@oucsace.cs.ohiou.edu (Bill White ) writes: >a very large van de graaff generator (about 4' high, fed with a 10kV >charge screen, hoping for up to 1MV if I'm lucky and running in SF6). >Anyhow, I need the top sphere, which should be in the range of 16 to 20 >inches diameter Ever consider an aluminum foil covered styrofoam ball. Or perhaps spray paint the ball with a conductive paint. Seems like it would be a fairly simple task to build a sphere lathe (maybe a hotwire template that you rotate the ball through.) Then you could build an optimum shaped anode, which is more mushroom shaped than purely spherical. -- - John Logajan @ Network Systems; 7600 Boone Ave; Brooklyn Park, MN 55428 - logajan@ns.network.com, 612-424-4888, Fax 612-424-2853